Simulation of Start-Up Transient Process for Hydroxylamine Nitrate-Based Liquid Monopropellant Rocket Engine

Non-toxic monopropellant engine is one of the key research direction of space propulsion. Aiming at the starting process of hydroxylamine nitrate (HAN) monopropellant rocket engine, the zero-dimensional model, simulation models with and without phase change process were established and applied to simulate the starting process of a 60N rocket engine. The calculation results show that the starting process of the chamber pressure goes through two stages, which corresponding to a fast process of the gas filling and a slow process of the temperature rise of the catalyst bed, respectively. The results calculated by the zero-dimensional model and the CFD method without phase change are nearly identical. The duration of the first stage is significantly shorter than that of the test, and that of the second stage agrees well with the test. The results calculated by the model with the phase change of the liquid propellant agree well with the test. One-dimensional calculation shows that the HAN-based monopropellant decomposes completely within the length of about 4 mm entering the catalytic bed. Catalytic reaction has an great influence on the first stage of pressurization, and the rate of decomposition of HAN-based monopropellant is much lower than that of hydrazine. © 2020, Editorial Department of Journal of Propulsion Technology. All right reserved.